June 2000 Observing Plan
version 2.0 2000-June-16; 19:40am(rgm@ioa)
Run dates: Mon June 12 to Thur 22 June, 2000
- 12-15 ELAIS CAT(INT/00A/C16: Perez-Fournon)
[ Proposal ]
- 16-22 Survey PATT(INT/00A/P16: McMahon)
[ Proposal ]
Note this ELAIS CIRSI CAT survey proposal is different from the
ELAIS CIRSI ITP survey proposal. In the ITP run in May we did
a shallow survey with an exposure time of 10mins in H whereas
in the June CAT run the goal is to go deep in a single 4-pointing
tile.
How much time do we have available
Each night there is 6.9hrs between astronomical twilight. However we may
be able to get 7.9hrs is we observe between 12degree twilights. We should
aim for this. This means do a snafu on a V=5 star soon after sunset.
Lets assume 7hrs per night and 50% of time is used for science observations.
This gives:
CIRSI Grid and Tiling Pattern
The nominal size of filled CIRSI tile is 29.6'x29.6'. The chosen
step size for the tiling is 28'x28'
see cirsi_grid.pl for the tiling pattern.
Other useful material:
Version 2 observing plan for the June PATT run
Standard stars required are listed in the INT CIRSI Observing Guide
Defocus by 0.2units for standards REMEMBER TO SET IT
BACK AFTERWARDS. Best do a standard just before you start or at the
end survey regions ie before a long slew.
Focus after every long slew eg around 3 times per night in total
- Observe XMM XMM Lockman Hole field in J and H
- 10 53 23.1 +57 32 57 J2000.0:
This field
is a deep XMM pointing that will go public on July 10th. Lots of
PR possible, especially if we do the field properly during the WFC
run as well
- 4 loops of 30seconds
- 5 point dither
- aim for 10mins per pointing per night in 2-3 pointings from the
the full tile
- cycle through the pointings for 2-3 nights in H and then repeat
in J.
- aim for at least 10mins per band per pointing
- 1 tile at 10mins per pointing in both J and H will
require 80 minutes on sky
- try to get more than 20mins in total per pointing if
time permits. Maybe 20in H and 10 in J.
- ELAIS-N1 complete a grid of 5x5 CIRSI tiles in H,
centred in the ELAIS 5 tiles that have been completed.
- 20 CIRSI tiles needed the same depth as the ITP survey
- 3 loops of 30sec [or 4 of 22sec when sky is too bright for 30sec]
- 4 dithers
- 4 pointings per tile
- on sky time is 6mins per pointing; 24mins per tile
- to do 20 tiles requires 480minutes on sky
- ELAIS N2: complete a grid of 3x3 CIRSI tiles in H
- 4 CIRSI tiles needed
- to do 4 tiles requires 96minutes on sky
- J and H images of 1 Feltzing/Gilmore/Wyse galactic clusters that
were observed in a previous PATT run
- NGC6633(1828+0634), NGC7092(2134+4832)
- 3 loops of 30secs per band
- 4 dithers per position
- 24 minutes per tile per band
- requires 96minutes on sky
- Galactic Centre(1745-2856)
- PR and confusion analysis
- 3 loops of 30secs per band
- 4 dithers per position
- 24 minutes per tile per band
- requires 48minutes on sky
- SSA22 WFS/CFHT Survey region
- 1 tile
- J and H
- 4 loops of 30secs per band
- 5 dithers per position
- 10 minutes per tile
- requires 80minutes on sky
- WFS dec=0 strip 2200 to 2300
- 3 loops of 30sec [or 4 of 22sec when sky is too bright for 30sec]
- 4 dithers
- 4 pointings per tile
- on sky time is 6mins per pointing; 24mins per tile
- assume on average 1 tile per night
- requires a minimum of 168minutes on sky
- Standards
- observe the LCIRS standard stars in J and H at least twice
during the run so that we can compare the system throughput
at the INT and the DuPont directly.
Total time
The above program adds up to 948 minutes on sky.
Other suggestions
If the above program is completed, I suggest getting J band data in the
ELAIS-N1 region with the same observing strategy. You might increase
the exposure time per loop in J but decrease the number of dither
to be more efficientm but keep the total time per pointing the
same.
Expand the coverage in the N2 region beyond the 3x3 grid. If
you do this please make sure the region is imaged in the
WFC run.
Expanding to 5x5 would require 16x24mins = 384minutes on sky
What did we say we would do in our proposal
- we said we would expose for 300second per pointing
- assumed 8.4hrs per night scheduled in mid-May; this
should have said 7.4hrs!
- 60% observing efficiency
- asked for 14nights of 8.4hrs => 117.6hrs
- proposed to cover 25deg^2 in J and H.
- actual allocation was 7 nights of 6.9hrs => 46.2hrs
- i.e. 39.3% of requested amount
How do we get some J coverage
To get some J we have a number of options;
- descope of the H coverage
- reduce the H band exposure times
- reduce the observing overheads
One option would be to cover 1.5degx1.5deg regions in the ELAIS N1
and N2 regions in J for 360secs per pointing. This would give us
around 4.5deg^2 of J data. It would require:
- 72 pointings of 360seconds
- 432minutes on sky
Going shorter than 360seconds with the current CIRSI software is
quite inefficient.